This invention relates to a light-sensitive silver halide color photographic material, more particularly to a light-sensitive silver halide color photographic material (hereinafter referred to merely as light-sensitive material) which is improved in graininess, sharpness and pressure fogging resistance of the image.
In the field of light-sensitive materials, development of light-sensitive materials having high sensitivity and containing micropulverized grains is strongly desired particularly in recent years, and a large number of improved light-sensitive materials for color photography have been proposed.
For instance, German Pat. No. 1,121,470 and U.K. Pat. No. 923,045 state that sensitivity can be enhanced without deterioration of graininess by providing by coating separately in layers a high sensitivity silver halide emulsion layer and a low sensitivity silver halide emulsion layer each containing a dye image forming coupler capable of color forming to substantially the same hue, and further controlling the maximum color-formed density of the above high sensitivity silverhalide emulsion level at a low level.
However, according to the method as mentioned above, the oxidized product of a p-phenylenediamine type color developing agent formed by development of coarse silver halide grains in the high sensitivity silver halide emulsion layer subjected to exposure does not remain within the above high sensitivity silver halide emulsion layer but migrates by diffusion to the adjacent low sensitivity silver halide emulsion layer having higher coupler density, where large dye grains are formed resulting in disadvantageous deterioration of graininess.
Also, in recent years, higher sensitization is increasingly demanded, and coarse silver halide grains inferior in graininess and a coupler with great coupling speed are obliged to be used in emulsion layers. Accordingly, graininess can necessarily be improved only insufficiently and it has been desired to make efforts for further improvement of graininess.
As a part of such improvement, for instance, Japanese Patent Publication No. 15495/1974 and Japanese Unexamined Patent Publication No. 7230/1978 disclose a method in which a medium sensitivity silver halide emulsion layer lower in color-formed density and a medium sensitivity silver halide emulsion layer containing a DIR compound are provided by coating between a high sensitivity silver halide emulsion layer and a low sensitivity silver halide emulsion layer.
However, these methods involve a drawback that the extent of improvement of graininess is insufficient in the gradation region where graininess is most conspicuous during photographing.
Further, Japanese Unexamined Patent Publication No. 155536/1982 states that a light-sensitive material excellent in both high sensitivity and graininess can be obtained by providing a non-sensitive intermediate layer containing a dye image forming coupler between a high sensitivity silver halide emulsion layer and a low sensitivity silver halide emulsion layer having light-sensitivity to substantially the same spectral region. However, even according to such a method, graininess in the medium density region where graininess is most conspicuous is not yet sufficient.